textproduct: Rapid City

KEY MESSAGES

-Warmer than normal temperatures linger through Tuesday

-Elevated to near critical fire weather conditions Sunday

-Wildfire smoke is expected to linger indefinitely, with thicker smoke at times

-Dry most areas through this weekend, the exception will be isolated thunderstorm south central SD tonight and across northwest into central SD Sunday evening

-Becoming unsettled and cooler next week

UPDATE

Issued at 933 PM MDT Sat Aug 8 2026

Weak impulse will support isolated TS chances across south central SD tonight. There is enough CAPE and deep layer shear to support a brief severe storm if enough forcing is realized. Dry Sunday most places. Kept pops out of the BH in the afternoon given very dry profiles. However, a stronger updraft could support a brief shower in the northern BH in the afternoon. Otherwise, the next impusle will support isolated TS chances across northwest into central SD Sun evening. Deep moisture eventually builds into the region through mid next week with gradually increasing chances for showers and storms with each impulse. Shear will also increase as faster flow shifts south over the FA, supporting an increasing severe threat.

DISCUSSION

(This Afternoon Through Friday) Issued at 1147 AM MDT Sat Aug 8 2026

It has been another clear sky day with hazy conditions. Latest air quality index is at the Moderate level with some isolated spots in the Unhealthy for Sensitive Groups. Looking ahead, a passing cool front will give some low-end shower and storm chances for parts of the southern SD plains this evening. Locally heavy rainfall rates, lightning, and strong gusty winds are the main concerns. Afterwards, skies will be quiet as temps cool to the upper 50s to lower 60s.

Sunday will be an interesting day to see play out. Machine learning severe weather probability models have been highlighting an elevated risk for severe weather on Sunday for multiple days now. But hi-res short term models are hesitant to allow convection to happen. Mostly likely for several reasons, like how dry it is and how warm the atmosphere will be. But either way, the consensus is, if storms are able to get going, they could be strong to severe. The SPC has placed a Marginal over most of the SD counties with a Slight over the central SD counties. If storms are able to initiate, thinking is that they would begin near and in the Black Hills before drifting eastward into the SD plains. Main concerns would be wind and lightning.

Otherwise, skies will be on the sunnier side with lingering haze tomorrow. Afternoon temps will reach the low to mid 90s for most, a little cooler for some in the Black Hills and in northern SD.

Monday and Tuesday look similar, with highs mostly in the upper 80s to lower 90s. Zonal flow will keep the daily chances for afternoon storms in place over the CWA.

Unsettled pattern under zonal flow will give the area cooler temps and daily chances for rain and storms for the second half of the week.

AVIATION

(For the 06Z TAFS Through 06Z Sunday Night) Issued At 1016 PM MDT Sat Aug 8 2026

VFR conditions are expected through the TAF period. An isolated thunderstorm or two is possible for south-central South Dakota through 09/08z. Transient MVFR conditions are possible around any heavier precipitation cores. Smoke will continue to linger over northeastern Wyoming, however, visibility impacts should remain minimal through the TAF period.

FIRE WEATHER

Issued At 930 PM MDT Sat Aug 8 2026

Widespread elevated conditions can be expected Sunday, with critical conditions across portions of northeast WY due to breezy westerly winds and low RH. A small, quick moving low pressure center could initiate thunderstorms in the afternoon in and near the Black Hills. Those storms would then drift east. Concerns for these storms will again be strong, erratic wind gusts and frequent lightning. A cooling trend can be expected next week with unsettled conditions.

UNR WATCHES/WARNINGS/ADVISORIES

SD...None. WY...Red Flag Warning from noon to 8 PM MDT Sunday for WYZ315-317.